Many changes are taking place in the way wireless communication networks are being deployed. Some of the changes are being driven by the adoption of new mobile communications standards. The introduction of software defined radios to wireless telecommunications has led to the generation of software and hardware solutions to meet the new standards. Current mobile communication standards introduce physical and logical channels and pose new issues in the transport of information within the communication networks.
A software defined radio (SDR) uses software for the modulation and demodulation of radio signals. The use of reprogrammable software allows key radio parameters, such as frequency and modulation protocols to be modified without the need to alter the underlying hardware of the system. Additionally, SDRs allow a single device to support multiple configurations which previously would have required multiple hardware devices. One example of a software defined radio is the Vanu Software Radio produced by Vanu, Inc. (See U.S. Pat. No. 6,654,428).
Some modulation standards that wireless communication networks operate with include, but are not limited to, Advanced Mobile Phone System (AMPS), code division multiple access (CDMA), Wide-band CDMA (WCDMA), time division multiple access (TDMA), Global System for Mobile communications (GSM), Cellular Digital Packet Data (CDPD), Enhanced Data rates for GSM Evolution (EDGE), General Packet Radio Service (GPRS), Integrated Digital Enhanced Network (iDEN), and Orthogonal Frequency Division Multiplexing (OFDM).
In standards that implement digital processing of voice and data communications, data streams typically carry digital samples of the voice and data communications in the form of digital words of a finite bit length and multiplex into a single data stream digital words comprising voice and data communications for several end users of the communications network. Often, a plurality of digital words are bundled together into groups or pages to increase the processing efficiency of communications network systems. Because of this, various network systems must maintain synchronization to ensure agreement about which digital words in a data stream belong to the same group.
When the transmission of digital words in a data stream are processed by network systems at either a slower or faster rate than expected, based on the modulation standard, then network buffers may unexpectedly empty or fill resulting in either gaps in the data stream, or lost data. One undesired consequence of unexpectedly empty or filled buffers is the loss of synchronization between components within the communications network.
For the reasons stated above, and for other reasons stated below that will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art today for methods and systems for handling buffer underflows and overflows while maintaining synchronization between system components.